At first guess, most people would say this is a Monarch butterfly. It's not, it is a Viceroy. Viceroy's mimic Monarchs in the coloring, flight patterns and habits. They are slightly smaller sized and have a different pattern and markings on their wings. This poor fellow has seen better days. He's missing a wing tip and an antennae.
You might be offended by the background in which I photographed this butterfly, but it is actually a common place to find many butterflies. They love gravel and crushed limestone paths. It provides them with important minerals and salts for their diet.